The way I see it, wizards and profs are meant to force the enemy to use GTB, so a champ can asura them. (WoE)
A wizard is one of the best supporting classes here, since they force the enemy to wear GTB, or at least strong shield and elemental resist gear, and if you get really lucky the enemy freezes as well.
Wizards can still deal insane amounts of damage here, since agi reduces the skill animation duration, so low-delay skills like JT, and some others if you have kiels, can be spammed insanely fast. Get their gtb off, force them to use usakoring by having a champ to support you, then hit them hard at the right moment.
EDIT: I forgot to mention, I only use GTB when either a wiz is SGing me to freeze so his champ bud can asura me (I can still survive a GTB asura naturally, being a paladin, so the case above doesn't apply here, but then again paladins are naturally hard to kill), or somebody lame is comaing me (especially clowns.. good thing my GTB is on an unbreakable shield).